Communications devices can communicate with each other via inductive coupling. For example, near field communications (NFC) is a wireless technology based on radio frequency identification (RFID). NFC allows wireless connection between two devices in close proximity to each other to exchange data between the two devices. RFID transponder devices that utilize NFC typically can be configured for either passive load modulation (PLM) or active load modulation (ALM).
In a communications device that communicates via inductive coupling, automatic power control (APC) is used to control the load modulation amplitude (LMA) in response to the field-strength of inductive coupling to fulfill specification requirements. However, in a typical table-based APC approach, a static APC table is defined and tuned for a communications device, which requires multiple iterations of measurements and manual calculations. In addition, when the specific system configuration of a communications device changes, a new APC table needs to be generated from scratch, which can increase the computing and measurement overhead.